* {
  margin: 0;
  padding: 0;
}

body {
  background-color: #f3f5f7;
}

li {
  list-style: none;
}

a {
  text-decoration: none;
}

/* 版心宽度,水平居中 */
.w {
  width: 1200px;
  margin: auto;
}

.sticky {
  /* 粘性定位 */
   position: sticky;
   top: 0;
}

.header {
  height: 40px;
  margin: 30px auto;
}

.logo {
  float: left;
  width: 198px;
  height: 42px;
}

.nav {
  float: left;
  margin-left: 60px;
}

.nav ul li {
  float: left;
  margin: 0 15px;
}

.nav ul li a {
  display: block;
  height: 42px;
  padding: 0 10px;
  line-height: 42px;
  font-size: 18px;
  color: #050505;
}

.nav ul li a:hover {
  color: #00a4ff;
  border-bottom: 2px solid #00a4ff;
}

.search {
  float: left;
  width: 412px;
  height: 42px;
  margin-left: 70px;
}

.search input {
  float: left;
  width: 344px;
  height: 40px;
  border: 1px solid #00a4ff;
  border-right: 0;
  color: #bfbfbf;
  font-size: 14px;
  padding-left: 15px;
}

.search button {
  float: left;
  width: 50px;
  height: 42px;
  /* 去掉按钮默认边框 */
  border: 0;
  background-image: url(../img/btn.png);
}

.user {
  float: right;
  line-height: 42px;
  margin-right: 30px;
  font-size: 14px;
  color: #666;
}

.user img {
  vertical-align: middle;
}

.banner {
  height: 420px;
  background-color: #1c036c;
}

.banner .w {
  height: 420px;
  background: url(../img/banner2.png) no-repeat top center;
}

.side-nav {
  float: left;
  width: 190px;
  height: 420px;
  background: rgba(0, 0, 0, .3);
}

.side-nav ul li {
  height: 46px;
  line-height: 46px;
  padding: 0 20px;
}

.side-nav ul li a {
  font-size: 14px;
  color: #fff;
}

.side-nav ul li:hover {
  background-color: #0091df;
}

/* 右向小箭头 */
.side-nav ul li a span {
  float: right;
  width: 5px;
  height: 46px;
  background: url(../img/s-arrow-right.png) no-repeat center center;
}

.course {
  float: right;
  width: 230px;
  height: 300px;
  background-color: #fff;
  margin-top: 50px;
}

.course h2 {
  height: 48px;
  background-color: #00a4ff;
  font-size: 18px;
  line-height: 48px;
  text-align: center;
  color: #fff;
}

.bd {
  padding: 0 20px;
}

.bd ul li {
  padding: 14px 0;
  border-bottom: 1px solid #ccc;
}

.bd ul li:last-child {
  border-bottom: 0;
}

.bd ul li h4 a{
  font-size: 16px;
  color: #4e4e4e;
}

.bd ul li h4 a i {
  font-style: normal;
  font-size: 14px;
  color: #2c4858;
}

.bd ul li h4 a i:hover {
  color: turquoise;
}

.bd ul li p {
  font-size: 12px;
  color: #a5a5a5;
}

.bd .more {
  display: block;
  height: 38px;
  border: 1px solid #00a4ff;
  text-align: center;
  line-height: 38px;
  font-size: 16px;
  font-weight: 700;
}

.bd .more:hover {
  background-color: #00a4ff;
  color: #fff;
}

.goods {
  height: 60px;
  background-color: #fff;
  margin-top: 10px;
  /* 行高继承给子元素 */
  line-height: 60px;
  box-shadow: 0 2px 3px 3px rgba(0, 0, 0, .1);
}

.goods h3 {
  float: left;
  margin-left: 30px;
  font-size: 16px;
  color: #00a4ff;
}

.goods ul {
  float: left;
  margin-left: 30px;
}

.goods ul li {
  float: left;
  text-align: center;
}

.mod {
  float: right;
  margin-right: 30px;
  font-size: 14px;
  color: #00a4ff;
}

.mod:hover {
  text-decoration: underline;
}

.goods ul li a {
  padding: 0 30px;
  font-size: 16px;
  color: #050505;
  border-left: 1px solid #bfbfbf;
}

.goods ul li a:hover {
  color: #00a4ff;
}

.main {
  margin-top: 20px;
}

.main-hd {
  height: 45px;
}

.main-hd h3 {
  float: left;
  font-size: 20px;
  color: #494949;
  margin-left: 15px;
}

.main-hd a {
  float: right;
  font-size: 12px;
  color: #a5a5a5;
  margin: 10px 30px 0 0;
}

/* 将父级ul修改到足够宽,能容下一行五个li */
.main-bd ul {
  width: 1225px;
}

.main-bd ul li {
  /* 父相 */
  position: relative;
  float: left;
  margin:0 15px 15px 0;
  width: 228px;
  height: 270px;
  background-color: #fff;
}

.main-bd ul li>img {
  width: 100%;
}

.main-bd ul li h4 {
  margin: 20px 20px 20px 25px;
  font-size: 14px;
  font-weight: 400;
  color: #050505;
}

.main-bd .info {
  margin: 0 20px 0 25px;
  font-size: 12px;
  color: #999;
}

.main-bd .info span {
  color: #ff7c2d;
}

/* 双伪清除浮动 */
.clearfix:before,.clearfix:after {
  content: "";
  display: table;
}

.clearfix:after {
  clear:both;
 }

.clearfix {
  /* IE6,7 */
  *zoom: 1;
 }

 .footer {
   height: 415px;
   background-color: #fff;
 }

 /* 考虑到外边距合并导致父元素外边距塌陷问题,可以采用内边距 */
 .footer .w {
   padding-top: 35px;
 }

 .copyright {
   float: left;
 }

.copyright img {
  margin-bottom: 20px;
}

 .copyright p {
   font-size: 12px;
   color: #666666;
 }

  .copyright .app {
    display: block;
    width: 118px;
    height: 33px;
    margin-top: 15px;
    border: 1px solid #00a4ff;
    text-align: center;
    line-height: 33px;
    color: #00a4ff;
    font-size: 16px;
  }

 .links {
   float: right;
 }

 .links dl {
   float: left;
   margin-left: 100px;
 }

.links dl dt {
  font-size: 16px;
  color: #333;
  margin-bottom: 5px;
}

.links dl dd a{
  font-size: 12px;
  color: #333;
}

/* 瞩目小角标 */
.main-bd ul li em {
  /* 子绝 */
  position: absolute;
  top: 4px;
  right: -4px;
}

.to-top {
  position: fixed;
  left: 50%;
  bottom: 80px;
  margin-left: 610px;
}

.to-top img {
  cursor: pointer;
}
